Dubnium is a synthetic element that was discovered in 1970. It is highly radioactive and unstable element.
History and Discovery
Dubnium was synthesized for the first time by team of scientist working at the Joint Institute for Nuclear Research (JINR), Dubna, Russia in 1968 and later the scientists of American Lawrence Berkeley Laboratory (LBL) announced the discovery of element-105 in 1970. The JINR team bombarded an americium-243 target with neon-22 ions and produced an two atoms of element 105, dubnium-261 and dubnium-260. The LBL team bombarded a californium-249 target with nitrogen-145 ions and produced element 105 [1]. International Union of Pure and Applied Chemistry (IUPAC) confirmed the name dubnium in 1997 after the town Dubna where Joint Institute for Nuclear Research (JINR) was located [2]. The symbol of dubnium is Db.
Dubnium
| Periodic Table Classification | Group 5 Period 7 |
|---|---|
| State at 20C | Solid (predicted) |
| Color | n/a |
| Electron Configuration | [Rn] 5f14 6d3 7s2 |
| Electron Number | 105 |
| Proton Number | 105 |
| Electron Shell | 2, 8, 18, 32, 32, 11, 2 |
| Density | 29.30 g.cm-3 at 20°C (predicted) |
| Atomic number | 105 |
| Atomic Mass | 262.00 g.mol -1 |
| Electronegativity according to Pauling | n/a |
Occurrence
Dubnium is an artificial element and does not exist in nature and only is produced in a laboratory.
Physical Characteristics
Dubnium is predicted to be a solid under normal conditions. The unstable nature of dubnium makes it difficult to carry out a statistically significant analysis of its physical and chemical characteristics. Dubnium is a very heavy element. The expected density of dubnium is around 29.3 g/cm3.
Chemical Characteristics
The chemical characteristics of dubnium have not been well studied yet. Dubnium is a transition metal that belongs to the 6d series, group 5 of the periodic table. It is placed under niobium, vanadium and tantalum and is predicted to have similarity with these elements, especially niobium. The most common oxidation state of dubnium have been predicted to be +5.
Significance and Uses
- Dubnium is used for research purposes.
Health Effects
Dubnium is a radioactive element and requires special precautions with handling and storage.
Isotopes of Dubnium
There are six main isotopes of dubnium, with mass number ranging from 262, 263, 266, 267 268 and 270. They are unstable and unnatural [3]. The most stable isotope is dubnium-268 that has a half-life of 28 hours. Most of the isotope of dubnium undergo decay through emission of alpha particles.
REFERENCES
[1]. Barber, Robert C; Greenwood, N. N; Hrynkiewicz, A. Z; Jeannin, Y. P; Lefort, M; Sakai, M; Ulehla, I; Wapstra, A. H; Wilkinson, D. H (1993). “Discovery of the Transfermium elements” (PDF). Pure and Applied Chemistry. 65 (8): 1757. doi:10.1351/pac199365081757. Retrieved September 7, 2016
[2]. Hoffman, D. C.; Ghiorso, A.; Seaborg, G. T. (2000). The Transuranium People: The Inside Story. Imperial College Press. pp. 369–399. ISBN 978-1-86094-087-3
[3]. Karpov, A. V.; Zagrebaev, V. I.; Palenzuela, Y. M.; Greiner, W. (2013). “Superheavy Nuclei: Decay and Stability”. In Greiner, W. Exciting Interdisciplinary Physics. FIAS Interdisciplinary Science Series. Springer International Publishing. pp. 69–79. doi:10.1007/978-3-319-00047-3_6. ISBN 978-3-319-00046-6